LCD showing mostly jibberish on 16F716

[davewanna]

I noticed the LCD_BITS 4 line in your code. I've never used that line before and always used 4-bit LCDs. I added it anyway and no change. I also changed the LCD init line to same as yours, and outputted everything on one LCDOUT command like you. Same result.

I'm sure I recall using a specific command to use the internal osc in the past, whereas this datasheet indicates clearing option register bit 5 will turn it on?
To be honest I don't really know how to set the option register bits with the setup I am using now. I'm using the dos-based pickit2 so I don't get to choose the option bits before I hit program.

I feel stupid for claiming I've done this before but not knowing how to set option reg bits.

[davewanna]

After reading more datasheet and looking at the PBP inc file for this chip, the best I came up with in my tired state is to change my first line to....

@ __CONFIG _WDT_ON & _RC_OSC & _PWRTE_ON & OPTION_REG = %11011000

Now I'm sure this is wrong, can anyone point me to the idiots guide to setting option regs?
Thanks

[davewanna]

Henrik,

That would explain why I can't find an easy way of turning it on and off. Having said that, in my circuit the OSC pins are left floating. How is it doing anything?

Edit: I think you're right Henrik, I've been trying to make it do something it isn't meant to do.
I will add a crystal osc tomorrow and change the osc source and see how I go.
Thanks

[HenrikOlsson]

Yeah, with the OSC pins floating it might be picking up noise and running off of that.
For that device you need an external crystal/resonator or an external R/C network - or an external clock signal for that matter. With both OSC pins floating you have neither.

/Henrik.

[davewanna]

You're exactly right Henrick.
I put a 4Mhz osc on it thismorning, works perfectly.

I'm surprised it worked at all with no external osc components.

Cheers

[Scampy]

I must admit I'm surprised that it doesn't have a built in oscillator. Thought that all pics had that ??

[HenrikOlsson]

Hi,
Actually, according to the product selector on Microchips website only 18 out of around 375 models (which are in production) is missing an internal oscillator of one type or another. They are:

PIC16F54
PIC16F57
PIC16F716
PIC16F59
PIC16F1454
PIC16F1455
PIC16F1459
PIC16HV540
PIC16F818
PIC16F819
PIC16F72
PIC16F73
PIC16F84A
PIC16F74
PIC16F76
PIC16F77
PIC18F6520
PIC18F8520

So it's close but not quite all ;-)

/Henrik.